Internal-combustion engine



Oct. 6, 1953 J wn- 2,654,357

INTERNAL-COMBUSTION ENGINE Filed Aug. 15, 1950 INVENTQR v fi ial E.

KILL in. ,lqzfirs Patented Oct. 6, 1953 2,654,357 INTERNAL-COMBUSTION ENGINE Julius E. Witzky, Royal Oak, Mich., assignor to Packard Motor Car Company, Detroit, Mich., a corporation of Michigan Application August 15, 1950, Serial No. 119,493

Claims. (01. 123-193) In the manufacture and assembly of internal combustion engines of relatively large size, it is customary to cast the cylinder block, cooling jacket, and part of the crankcase as a unit, providing cylindrical recesses or openings for the reception of separately formed removable cylinders. The cylinders themselves, very obviously, are subject to great wear and are therefore made of high quality alloys, and this method of construction renders them readily replaceable when the need arises. Although aimed at facility in repair and replacement, the provisions heretofore made for securing the cylinders in the block have not been conducive either to ease or efficiency in removing and replacing the cylinders, in protecting the block or cylinder parts, nor in ensuring the clamping of the cylinder in place with such uniformity of pressure or force throughout its periphery which will prevent setting up uneven stresses in the assembled structure.

It is therefore the purpose of the present invention to provide novel and improved means for clamping a removable cylinder in place in the block of an internal combustion engine, which will correct these deficiencies and attain the desired facility, safety, and accuracy of installation.

In ordinarypractice the cylinders have been secured in place by the use of a multiplicity of studs or bolts requiring a great number of tightening operations and giving rise to undesirable stresses due to lack of uniformity of the application of tightening pressure. These current practices also create undesirable concentration of stress at local points due to the application of the tightening load at a few separated points. The present invention, however, contemplates the provision of a single large cylindrical retaining nut, threaded into the mouth of the cy inder recess or opening in the engine block casting, and applying a uniform clamping force around the edge of the top surface of the cylinder head by means of a sin le tightening operation.

Although the embodiment of the invention illustrated and described herein involves the securing of a composite pre-assembled cylinder head and valve in a diesel engine, similar to the one shown in the copending application of Ralph E. Van Deventer, Serial No. 157,762, filed April 24, 1950, the invention in its broadest aspects is not limited to this specific assembly but finds application to a wide variety of internal combustion engines.

Other objects and features of novelty will be apparent from the following specification when read in connection with the accompanying drawings in which one embodiment of the invention is illustrated by way of example.

In the drawings:

Figure 1 is a vertical sectional view through an engine block with part of the crankcase portion broken away;

Figure 2 is an enlarged sectional view showing the details of the threading of the clamping nut in the mouth of the cylinder opening;

Figure 3 is a view in side elevation of a removable thread insert employed in the application of the clamping nut;

Figure 4 is an end view of the coiled thread insert; and

Figure 5 is a fragmentary end view of the insert as viewed from the opposite end of the coil.

The engine block casting is indicated generally by the reference numeral ID. This casting includes the cylinder portion H and the crankcase portion I3. The block i I is provided with a series of recesses I5, each of which is adapted to receive a removable and replaceable cylinder designated generally by the numeral l6 and comprising a head portion I7 and a barrel portion [3. Thedmmediate concern of the present invention isfwith the cylinder block it and the provisions for securely and accurately fixing the replaceable cylinders therein. Other operative parts of the installation, for instance, those necessary to the proper supplying of fuel to the cylinder, are suggested in the drawings, but since they comprise no part of the present invention they need not be described.

The recess or opening I5 in the block for the reception'of the cylinder It is interrupted at an intermediate point spaced below the mouth thereof by a shoulder 20 against which the lower por tion of the cylinder head I! abuts when the cylinder is inserted and moved downwardly in the opening. This serves to fix the operative position of the cylinder within the block.

The upper end portion or mouth of the opening, as best shown in the enlarged view of Figure 2, is widened slightly from the bore or diameter indicated at l5, within which the cylinder I6 fits, to provide a threaded radially inwardly directed flange portion 22, this portion being preferably undercut by a groove 23. The threads 24 of the flanged opening or mouth of the recess are adapted to be engaged either directly or through the intermediary of a thread insert, by thethreads of a clampin nut 25.

Between the top surface 26 of the cylinder head 3 l1 and the lower surface of the clamping nut 25 there is preferably interposed a spacer ring 21. Preferably the spacer ring is provided with a groove '28 adapted to receive a packing ring 30 which effectively seals the opening I above the cylinder.

The locking ring 25 itself bears firmly upon the spacer ring 2'! and thereby pressure is applied to' the cylinder head clamping it rigidly against the shoulder 29. The threads 32 of the locking ring are preferably cut so as to just clear the threads 24 on the inner wallof the block flange 22 and in order to secure engagement of the sets of threads, there is provided a helical in sert 35 which is clearly shown as a separatcal'r ticle in Figures 3, 4 and 5 of the drawings. The,

claims.

Having thusdescribed the invention, what is claimed as new-and desired to be secured by Letters Patent is: 4

amond shape in cross-sectionso as to-provid'ethreading engagement with both set of threads 24 and 32 of the block opening and the locking ring respectively. I

By the use of such a thread insert, the threads of the cylinder opening are protectedfrom wear which might be occasioned by repeated removal and application of ti e locking ring.

Inthe installation of the h'elical'thread insert 35, the insert is applied to the threads 24 of the lock first, either end of the coil being screwed into the threaded opening foremost, by means of a suitable tool which may be applied to the inwardly directed end 49 of the coil, which stub end may be broken off after the application of the insert if desired.

It will be noted that upon the outer periphcrie of the first and of the last convolutions of 3" the coil 35 for a distance of approximately of arc, there are provided a number of teeth E2 and G3. These teeth are provided for anchoring the insert with respect to the teeth 24 of the cylinder blo .1, the ends of the coil being forced radially outwardly into the root and flanks of the thread groove in the mouth of the block opening. After the insert has been installed in the threads of the opening, the locking ring 25 is applied by means of a suitable tool adapted to en;- gage the ribs 4 5 on the inner periphery of the ring, the teeth 32 of the locking ring engaging the projecting thread-like portions of the insert Jhich is secured against relative movement with respect to the block. Continued application of the ring 25, which is of a diameter approximating that of the cylinder, causes the ring to bear with an evenly distributed pressure against the spacer ring 2? and thus clamping the cylinder H5 firmly in place against the shoulder 29 with a uniform pressure exerted during a, single tightening operation.

It will be clearly understood that the thread insert may be replaced whenever necessary and serves as a protection for the threaded portion of the cylinder block or jacket casting, all relative motion taking place between the locking ring and the thread insert, rather than with respect to the threads of the jacket.

It will be perceived from the above descriptions that the applicant has provided a compact arrangement for securing the removable cylinders of internal combustion engines within the cylinder blocks, the threaded clamping rings being disposed within the lateral or circumferential confines of the cylinder itself so that adjacent cylinders may be disposed closely together without the necessity of allowing for the diameter of a cylinder embracing retaining ring. It will be further understood that the application of :1. Ind a internal combustion engine, a cylinder block provided with an opening adapted to receive a removable cylinder within which a piston is adapted to move when the fuel charge is fired, a cylinder completely received within said opening with its upper end disposed well below the outer .end of the mouth of said opening, said cylinder being closed at its outerend by an end wall between which wall and the piston the combustion gases are confined, a shoulder within said opening against which a portion of the cylinder abuts to limit its movement into said opening, at least the mouth of said opening being cylindrical and of slightly greater diameter than the external diameter of said cylinder, internal screw threads formed on the mouth of aid opening; and an annular clamping ring, externally threaded and screwed into the mouth of said opening above the closed outer end of said cylinder, and exerting bearing pressure upon the periphery of said closed outer end of said cylinder to clamp it securely against said shoulder, and thus prestressing the closed cylinder, which comprise the combustion chamber, against the explosive pressure of the combustion gases.

2. In an internal combustion engine, a cylinder block provided with an opening adapted to receive a removable cylinder within which a piston isadapted to move when the fuel charge is fired, a cylinder received within said opening, stop means on the block against which a portion of the cylinder abuts to limit its movement into said opening, at least the mouth of said opening being cylindrical, internal screw threads formed on the mouth of said opening; a large clamping nut externally threaded and screwed into the mouth of said opening, and exerting bearing pressure upon the periphery of the outer end of said cylinder to clamp it securely and with uniformly distributed pressure against said stop means; a spacer element interposed between the top of said cylinder and the bottom of said clamping nutj and sealing means between said spacer element and the inner wall of the opening above the cylinder.

3. In an internal combustion engine, a cylinder block provided with an opening adapted to receive a removable cylinder within which a piston is adapted to move when the fuel charge is fired, a cylinder received within said opening, a shoulder within said opening against which a portion of the cylinder abuts to limit its movement into said opening, at least the mouth of said opening being cylindrical and of slightly greater diameter than the external diameter of said cylinder, internal screw threads formed on the mouth of said openin n annular clampg ring of approximately the diameter of said cylinder, externally threaded and screwed into the mouth of said opening, and exerting bearing su e. ,1 1. th periphe y o h buter end f said cylinder to clamp it securely and with uniformly distributed pressure against said shoulder; an annular spacer element interposed between the top of said cylinder and the bottom of said clamping nut; and a sealing ring compressed between said spacer element and the inner wall of the opening above the cylinder.

4. In an internal combustion engine, a cylinder block having an axially elongated substantially cylindrical opening therein adapted to receive a removable cylinder within which a piston is adapted to move when the fuel charge is fired, a cylinder including a cylinder head portion having an outer end wall, said cylinder including the cylinder head portion completely re ceived within said opening with the extreme end of said head portion disposed well within the mouth of said opening, stop means within said opening against which a portion of the cylinder abuts to limit its movement within said opening, at least the mouth of said opening being cylindrical and of a diameter sufiicient to receive the cylinder, internal screw threads in the mouth of said opening, and an annular clamping ring of approximately the diameter of the cylinder externally threaded and screwed into the mouth of said opening, said ring thus being located substantially within the transverse confines of the cylinder and exerting bearing pressure upon the periphery of the outer end wall of the cylinder to clamp it securely and with uniformly distributed pressure against said stop means, and serving effectively to stiffen and strengthen the entire structure.

5. In an internal combustion engine, a, cylinder block having an axially elongated substantially cylindrical opening therein adapted to receive a removable cylinder within which a piston is adapted to move when the fuel charge is fired, a cylinder including a cylinder head portion having an outer end wall, said head portion being of slightly greater diameter than the remainder of the cylinder thus providing a shoulder at its inner end, said cylinder including the cylinder head portion completely received within said'opening with the extreme end of said head portion disposed well within the mouth of said opening, stop means within said opening against which said shoulder abuts to limit its movement within said opening, at least the mouth of said opening being cylindrical and of a diameter sufficient to receive the cylinder head portion, internal screw threads in the mouth of said opening, and an annular clamping ring of approximately the diameter of the cylinder head portion externally threaded and screwed into the mouth of said opening, said ring thus being located substantially within the transverse confine of the cylinder head portion and exerting bearing pressure upon the periphery of the outer end wall of the cylinder head portion to clamp it securely and with uniformly distributed pressure against said stop means, and serving effectively to stiffen and strengthen the entire structure.

JULIUS E. WITZKY.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,208,744 Canhac Dec. 19, 1916 1,456,171 Woodward May 22, 1923 1,512,570 Andrews Oct. 21, 1924 2,055,814 Dennison Sept. 29, 1936 2,137,391 Chilton Nov. 22, 1938 2,301,235 Willgoos Nov. 10, 1942 

